Process of cracking hydrocarbon oil



Nov. 17, 1931. J. D. SEGUY PROCESS OF CRACKING HYDROCARBON OIL Original Filed Dec. 2'7, 1927 flan 1391a tire/27: W%?%, i45

Patented Nov. 17, 1931 UNITED STATES PATENT OFFICE JEAN DELATTBE SEGUY, OF CHICAGO, ILLINOIS, ASSIGNOB TQ UNIVERSAL OIL PROD- UCTS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA rnocnss or cmcxme HYDRO'CARBON on.

Application filed December 27, 1927, Serial No. 242,556. Renewed October 1, 1930.

The invention relates to the treatment of the vapors produced by previous cracking and more particularly to the treatment of vapors produced by liquid-vapor phase cracking process of the well known coil and chamber type.

The advantages and the objects of the invention will appear from the hereinafter filed description, and therefore, need not be where recited in detail. In order to more clearly understand the invention, I have shown the accompanying drawing, which is a diagrammatic view of an apparatus suitable for carrying out the invention, but it is un- 15 derstood that this drawing is diagrammatic and not to scale.

Referring to the drawing, 1 designates a furnace on which is mounted a heating or cracking coil 2. The coil is connected by as transfer line 3 having throttle valve 4 to the insulated reaction chamber 5. From the top of the reaction chamber 5, the vapors may pass through vapor line 6, having throttle valve 7 into the lower side of dephlegmator .8. The vapors which are not condensed in the dephlegmator pass out through vapor line 9 to condenser 10 and thence to receiver 11'. This receiver 11 has gas release control valve 12 and liquid discharge control valve 13.

The residue is drawn out through the lower part of the chamber 5 by draw-off pipe 14 connected to branch 15 leadin to the flash chamber 16. A pressure reducing valve 17 is interposed in the line 15. The lme 14 has a throttle valve 18. The residue from the dash chamber 16 is drawn out through pipe 19, having throttle valve 20. The vapors from the dash chamber 16 ass out through pipe 21, having throttle va ve 22a into a series of serially connected vapor phase cracking chambers 22. l have shown two in the drawing, but more than two can be used, if desired. Uhambers 22 have residue draw-ofis 23 controlled with throttle valve 24. From the last chamber 22 the va ors pass through pipe having throttle va ve 26, into the side of dephlegmator 27. From the top of this dephlegmator, the uncondensed vapors and gases pass through line 28 and condenser coil 59 29 to receiver 30. This receiver 30 has gas control valve 31 and distillate control valve 32.

To the dephlegmator 27 may be directly fed through pipe 33 having control valve 34, the raw charging stock, or if desired, the ten1- perature may be controlled by passing the raw charging stock through the closed coil 35,ihaving valves 36 and 37 and in the latter case, the preheated oil may be fed to the feed pump 38 and the main inlet line 39, leading to the coil 2. The reflux condensate and the preheated raw oil, if the latter is fed directly into the dephlegmator 27, pass through line 40' and pump 41 and line 42 to the inlet feed pipe 39.

The reflux condensate from the primary dephlegmator 8 may be fed to the line 21 through the pipe 43, having control valve 44, or the reflux from the main dephlegmator 8 may be fed through the line 45, having control valve 46 into the line 15 beyond thereducing valve 17. Also, if desired, the dephlegmator 8, condenser 10 and receiver 11 ma be cut out of the system and the vapors rom the chamber 5 pass to the line 21 through branch 47, having control valve 48.

The arrangement is such that in one method of carrying out the invention, the gasoline vapors and lighter gases will be separated in the dephlegmator 8 from the heavier reflux and then this reflux returned through the pipe 43, having control valve 44, in such case being used as a pressure reduc ing valve and the reflux flashed into the line 21 at the same pressure as is 'on the chamber 16. In such case, the valve 7 will be opened and the valves 48 and 46 closed.

Another method in which the invention may be operated would be to close the valves 44 and 48 and'use the valve 46 as a pressure reducing valve, whereby the reflux condensate will pass to the chamber 16. This might be desirable where the reflux condensate to dash is particularly heavy, and its heavier fractions will be removed through the line 19 with the residue. Another method of operating the invention would be to close the valves 7, 44 and 46 and pass all of the vapors through line 47, using the valve 48 as a pressure reducing valve.

2 resaeao I have provided means for effectively heat ing the vapors in chambers 22 by passing the flue gases from furnace 1 through the flue 49 in W ich is interposed a fan 50, this flue leading to the first chamber 22. The arrangement is such that the flue gases come into direct contact with the vapors and superheat them. It is, of course, desirable to control and, in some cases, within relatively narrow limits, the temperature in the chambers 22. To this end, I am interposinga cooling coil 51, having valves 52, in the flue 49 to cool the gases if too hot. If the gases are not hot enough, I provide an auxiliary heater 53, having flue 54 connected, as shown at 55, to the flue 49. The arrangement of this auxiliary heater is such that the gases of combustion may enter flue 49 under the pressure of the balance of the system. The use of flue gases in cracking the vapors is claimed in my copending applicaiton Serial No. 242,555 of even date.

In one method of carrying out the invention, incondensible gas and extraneous gas may be also introduced into the chambers 22 by means of the line 56, having valves 57. Preferably, this gas may be pre-heated by passing it through the heating coil 58, located in the heater 53 and the gas, introduced under sufiicient pressure to enter the-chambers 22, may be either inert gas, such as nitrogen or the like, or a hydrogenating gas, such as hydrogen. It may be carbon monoxide or carbon dioxide. It will be understood that in lieu of such gases steam may be employed.

Another method of operating the invention may be to close the damper 59 in the flue l9 and open the damper (50 in the branch 61. In such case, the heated gas introduced through the pipe 56 may be the only means for superheating the vapors in the chambers 22.

lln carrying out either of the above two last mentioned methods, the chambers 22 may be also externally heated through the turnaces 62.

Another method of carrying out the invention may be to put a catalyst, such as iron oxide or other suitable matter in the chamber 5, or the chambers 22, or in both of them. In all of the various methods above referred to, the oil may be subjected to a pressure of say 200 lbs. or more in the coil 2 and the chamher 5. The pressure in the chamber 16 and the dcphlegmator 8 and the chambers 22 and the dephlegmator 27 and its associated parts may be substantially lower than the pressure in the coil-say from 100 lbs. down to atmospheric pressure. Another manner of carrying out each of the foregoing methods would be to have a pressure of say 350 lbs. on the coil 2 and chamber 5, a pressure of say 100 lbs. on the chamber 16 and dcphlegmator 8 (in case the latter is not cut out of the system) while by regulating the reducing valve 63 on line 21 from 25 lbs. say to atmospheric pressure may be maintained on the chambers 22 and dephlegmator 27, or it desired, in the last mentioned case, a vacuum may be maintained in the chambers 22 by connecting a suitable vacuum pump, not shown, to the receiver 80.

In carrying out any of the methods above described, the degree of cracking in the liquid-vapor phase part of the system, to-wit, in the coil 2 and chamber 5, may be independently controlled relative to the degree of cracking in the vapor phase cracking chambers 22. Transfer temperature in the coil 2 may be say 850 F., more or less, while the temperature in the chambers 22 may be 1000 F., more or less.

By subjecting the vapors to vapor phase cracking in the chambers 22 with the gases therein contained in the manner heretofore described, gasoline containing relatively large percentages of anti-knock compounds may be formed. Also, other compounds may be formed, such as oxygenated compounds.

In carrying out any method of the above described process, it is desirable to have sub stantially complete combustion of the flue gases before they enter the chambers 25 in order to avoid combustion of the hydro-carbon vapors.

I claim as my invention:

1. A. process of cracking hydrocarbon oil consisting in subjecting the oil to a liquid va or hase ressure crackin reaction se )arately removing the generated vapors and liquid residue, subjecting the liquid residue to flash distillation at reduced pressure and then subjecting the first mentioned vapors and the vapors from said flash distillation to a vapor phase cracking reaction in the presence of a highly heated incondensible gas.

2. A process of cracking hydrocarbon oil consisting in subjecting the oil to a liquid vapor phase pressure cracking reaction, separately removing the generated vapors and liquid residue, subjecting the liquid residue to flash distillation at reduced pressure and then subjecting the first mentioned vapors and the vapors from said flash distillation to a vapor phase cracking reaction in the presence of a highly heated incondensible gas, and subjecting the vapors from said vapor phase cracking reaction to reflux condensation and then subjecting such reflux condensate to said liq uid'vapor phase pressure cracking reaction.

3. A process of cracking hydrocarbon oil consisting in subjecting such oil to a liquidvapor phase pressure cracking reaction, separating the oil into vapors and incondensible hydrocarbon gases on the one hand and heavier residue on the other hand, thence passing said vapors and incondensible gases through a vapor phase cracking zone simultaneously introducing extraneous heated incondensible gases into said vaporphase uid residue, reducing the pressure on the Ell residue to liberate further vapors therefrom by flash distillation and then subjecting all the vapors liberated in the process to va or phase cracking in the presence of a hig ly eated gas which is incondensible under the conditions of the process.

5. A hydrocarbon oil cracking process which comprises subjecting the oil to crack-. ing conditions of temperature and pressure,

separating evolved vapors from unvaporized oil, lowering the pressure on the unvaporized oil thereby flash distilling the same, combinin resultant flashed vapors with vapors initially evolved from the oil, and vapor phase cracking the mixture by contact with a highly heated flud which is incondensable at the cracking temperature of said vapors.

6. A hydrocarbon oil cracking process which comprises subjecting the oil to cracking conditions of temperature and pressure, separating evolved vapors from unvaporized oil, lowering the pressure on the unvaporized oil thereby flash distilling the same, combining resultant flashed vapors with vapors initially evolved from the oil, vapor p ase cracking the mixture by contact with a highly heated fluid which is incondensable at the cracking tem erature of said vapors, dephlegmating t e vapor phase cracked vapors thereby forming reflux'condensate, and returning said reflux condensate to the process for retreatinent,

7. A process for cracking hydrocarbonoil consisting in raising the oil to a cracking temperature while passing the oil through a heating coil and then passing said oil to an expansion chamber, maintaining a pressure substantially above atmospheric onvthe oil in said coil and chamber, removing evolved vapors from said chamber and subjecting them to a vapor phase cracking operation, removing the residue and subjecting it toflash distillation at reduced pressure and then subjecting the flash distilled vapors to vapor phase cracking.

8. A; process for cracking hydrocarbon oil consisting in raising the oil to a crackin temperature While passing the oil throug a heating coil and then assing said oil to an expansion chamber, maintainlng a pressure substantially above atmospheric on t e oil in said coil and chamber, removing evolved vapors from said chamber and subjecting them to a vapor phase cracking operation, removing the residue and subjecting it to flash distillation at reduced ...pnessure and then subjecting the flash distilledvapors'to vaporphase cracking, taking said vapors after subjection to vapor-phase cracking and subjecting them to reflux condensation and returning resultant reflux condensate to the process for further treatment.

9. A process for cracking hydrocarbon oil, consisting in passing the oil through a. heating coil and then into an expansion chamber wherein the oil is maintained under pressure substantially above atmospheric, re-

moving the sufliciently and insufficiently cracked vapors and incondensible gas from said chamber and subjecting them all to vapor phase cracking, withdrawing residual oil from said expansion chamber, reducing the pressure thereon and thereby subjecting it to flash distillation, and combining the vapors therefrom with the constituents being passed to said vapor phase cracking.

10. In processes for converting higher boiling point oil into lower boiling point products in which the high boiling point oil is subjected to pressure distillation at a cracking temperature, vapors separated from unvaporized liquid oil, the unvaporized liquid oil removed from the pressure distillation and the pressure thereon reduced to effect further distillation of such removed unvaporized oil by the contained heat thereof, the improvement which comprises subjecting the vapors separated from the unvaporized liquid oil in the pressure distillation and the vapors separated from the removed unvaporized liquid oil under said reduced pressure to a vapor phase cracking treatment.

11. In processes for converting higher boil ing. point oils into lower boiling point prodnets in which the high boiling point oil is subjected to pressure distillation at a crack-' ing temperature, vapors separated from unvaporized liquid oil, the unvaporized liquid oil removed from the pressure distillation and the pressure thereon reduced to effect further distillation of such removed unvaporized oil by the contained heat thereof, the improvement which comprises subjecting the vapors separated from the unvaporized liquid oil in the pressure distillation and the vapors separated from the removed unvaporized liquid oil under said reduced pressure to a vapor phase cracking treatment, and subjecting the vaporous products of the vapor phase cracking treatment to partial condensation to form reflux condensate and returning the reflux condensate for further treatment in the process.

12. A process for converting high boiling point hydrocarbons into low boiling point hydrocarbon oils, consisting in subjecting said high boiling point hydrocarbons to cracking conditions of temperature and pressure in a zone of reaction, removing the evolved vapors, flashing the residual oil un' der reduced pressure, and subjecting vapors therefrom together with vapors removed from said reaction zone to vapor phase crackmg.

13. In processes for converting higher boiling point oil into lower boiling point products in which the high boiling point oil is subjected to pressure distillation at a cracking temperature, vapors separated from unvaporized liquid oil, the unvaporized liquid oil removed from the pressure distillation and the pressure thereon reduced to eflect further distillation of such removed unvaporizer oil by the contained heat thereof, the improvement which comprises subjecting the vapors separated from the unvaporized liquid oil in the pressure distillation and the vapors separated from the removed unvaporized liquid oil under said reduced pressure to a vapor phase cracking treatment, and subjecting the vaporous products of the vapor phase cracking treatment to partial condensation to form reflux condensate and returning the reflux condensate for further treat ment in the process, by combining it with said high boiling point oils being subjected to pressure distillation.

J JEAN DELATTRE SEGUY. 

